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Population abundance is a critical metric in fisheries and conservation, but it is very difficult to measure accurately. Existing estimation methods present significant challenges: mark-recapture methods are time- and labour-intensive, and hydroacoustic echo counting methods face issues with target identity and the habitat types where they can be effectively applied. We present a new methodology for abundance estimation that can improve the reliability of echo counting methods. Split beam hydroacoustic survey data are integrated with telemetry data from fish bearing acoustic transponder tags. These tags are counted by a spatially and temporally concurrent multibeam acoustic survey to produce mark-recapture abundance estimates. We assessed this approach on four wild lake trout populations, ranging in abundance from ~200 to ~3000 adults. Our abundance estimates were consistent with those derived from conventional Schnabel and Jolly-Seber mark-recapture studies. We show that the precision achievable with this method in 1 year of field work rivals that provided by long-term (>10 years) continuous mark-recapture studies. We also discuss other ecological questions that could be addressed with this approach. Key words: estimating abundance, hydroacoustics, acoustic telemetry, mark- recapture, multibeam sonar, Introduction 'Managing fisheries is hard: it's like managing a forest, in which the trees are invisible and keep moving around'--John Shepherd Sustainable fisheries management requires the resource manager to ensure [...]

With the decline of many exploited fish populations, catch and release has become an increasingly used management practice to allow sport fishing while reducing its impact on wild populations. However, survival and reproductive success can vary according to the catch and release technique and environmental conditions, suggesting a potential impact of this practice on prespawning behaviour. Here we evaluate how some critical aspects of salmon freshwater migration are influenced by catch and release and by environmental factors. For this purpose, 40 multi-sea-winter Atlantic salmon (Salmo salar) (20 catch and release and 20 control) were followed by telemetry from June 2011 to March 2012. Temperature was found to influence movements and the daily probability that a fish would cross a fish ladder, while water discharge influenced daily distance travelled during the prespawning migration. Catch and release was found to influence the daily probability of fish to cross a barrier as well as the total distance traveled in the river. Overall, this study suggests that salmon caught and released by fishermen survive and reproduce, but that prespawning exploration behaviours could be altered compared with those of uncaught salmon. Avec le declin de plusieurs populations de poissons exploitees, la remise a l'eau est devenue une approche de gestion populaire afin d'assurer la peche sportive tout en minimisant ses impacts. Neanmoins, comme la survie et le succes reproducteur peuvent varier selon les conditions environnementales et la methode employee, la remise a l'eau pourrait avoir un impact non-negligeable sur le comportement pre-reproducteur. Cette etude evalue comment certains aspects critiques de la migration en eau douce du saumon atlantique (Salmo salar) sont influences par la remise a l'eau et les conditions environnementales. Quarante saumons redibermarins (20 remis a l'eau, 20 controles) ont ete suivis par telemetrie de juin 2011 a mars 2012. Les resultats indiquent que la temperature influence la probabilite de mouvement et de franchissement d'obstacle, alors que le debit influence la distance journaliere parcourue. Par ailleurs, la remise a l'eau influence la probabilite journaliere pour un individu de franchir un obstacle et la distance totale parcourue par celui-ci. Cette etude suggere que meme si les saumons remis a l'eau survivent et se reproduisent, le comportement pre-reproducteur peut en etre altere., Introduction As is the case with many other fishes worldwide, Atlantic salmon (Salmo salar) has been declining rapidly since the middle of the 20th century and is now near historic [...]

White-streaked grouper (Epinephelus ongus) is an important fishery target that forms fish spawning aggregations (FSAs) at specific spawning grounds. The aims of the present study were to investigate migration behavior and returning behavior in terms of FSA using acoustic telemetry. Among the 30 specimens tracked, three types of movement pattern were observed: type 1, high site fidelity at the release area before the spawning period, migration to the spawning ground during the spawning period and return to the release area just after the spawning period (17 specimens); type 2, high site fidelity at the release area, disappearance from the area during the spawning period but was not detected at the spawning ground and return to the release area (8 specimens); and type 3, high site fidelity at the release area was observed before, during and after the spawning period (5 specimens). For the 17 specimens that were categorized into type 1, the dates of departure from their release area and the dates of return to the release area of males were, respectively, significantly earlier and later than those of females. The duration between the departure date and the return date ('duration away') of males was significantly longer than that of females. The duration away tended to be positively related to the condition factor. All 25 specimens that were categorized as type 1 and type 2 showed returning behaviors to the release area., Introduction Some coral reef fishes form fish spawning aggregations (FSAs), and to date, over 80 species are known to form FSAs (Sadovy de Mitcheson and Colin 2012). FSAs are very [...]

Researchers often employ radio telemetry to locate study animals efficiently, but the time required to locate individuals can make monitoring large populations difficult and costly. In 2010-2011 we located nesting ornate box turtles (Terrapene ornata) in a large group of radio-tagged animals. To minimize search efforts, we investigated whether automated radio telemetry and the signal change method could be used to identify nesting activity before locating animals. The signal change method relies on the principle that any movement of a radio transmitter, including minor changes in orientation, can strongly affect the intensity of the transmitter's signal at a stationary receiving station. Using video recordings of free-ranging radio-tagged turtles, we confirmed that transmitter signal strength values can be analyzed to identity, periods of box turtle activity. Early in the 2010 nesting season, automated telemetry observations indicated that some females engaged in nocturnal activity. Previous reports indicate that ornate box turtles often nest at night but are otherwise inactive after dark. Based upon this information and relatively little indication of nocturnal activity by males, we hypothesized that nocturnal activity corresponded to nesting. We subsequently monitored female nighttime activity in near real time, hand-tracked four night-active individuals, and found three of these turtles nesting. In 2011 we again selectively hand-tracked night-active females and located nests for 12 of 18 study animals, which approximates the expected annual reproductive rate for our population. We demonstrate that the signal change method can be used to identify nesting activity in ornate box turtles and suggest this method may be of use in other species that nest outside of their normal activity periods., INTRODUCTION Behavioral data may be collected in the field by a variety of methods. Focal observations allow researchers to make detailed observations (Ruby and Niblick, 1994) but require significant time [...]

Sixteen satellite-tagged adult male loggerhead sea turtles (Caretta caretta) dispersed widely from an aggregation near Port Canaveral, Florida, USA (28°23'N, -80°32'W) after breeding. Northbound males migrated further (990 ± 303 km) than southbound males (577 ± 168 km) and transited more rapidly (median initial dive duration = 6 (IQR = 4-16) versus 19 (IQR = 10-31) min, respectively).. Migration occurred along a depth corridor (20-40 m) except where constricted by a narrow continental shelf width. Males foraged in areas 27 ± 41 km.sup.2 day.sup.-1 at locations, Author(s): Michael D. Arendt [sup.1] , Albert L. Segars [sup.1] , Julia I. Byrd [sup.1] , Jessica Boynton [sup.1] , Jeffrey A. Schwenter [sup.1] , J. David Whitaker [sup.1] , [...]

Thirty-four juvenile loggerhead sea turtles captured by trawling from the Charleston, South Carolina (USA), shipping channel (32°42'N; -79°47'W) between May 2004 and August 2007 were tagged with satellite transmitters to assess the extent to which they remained near the capture location given their collection along a seasonal migratory corridor. Seventy-five percent of juveniles were classified as seasonal residents. Migrants predominantly swam north in the spring and nomads wandered south in the summer, but predictive indicators for non-resident status were not identified. All but one juvenile generally remained south of 34°N, within 40 km of shore, and in waters 15 km from shore between spring and autumn were three times as likely to occur in oceanic habitats in winter. Modest seasonal movements contrasted with adults tagged at similar latitudes and with juveniles tagged further north and suggest distinct foraging groups within a regional foraging ground., Author(s): Michael D. Arendt [sup.1] , Albert L. Segars [sup.1] , Julia I. Byrd [sup.1] , Jessica Boynton [sup.1] , J. David Whitaker [sup.1] , Lindsey Parker [sup.2] , David [...]

Stereotypical changes in pH occur along the gastrointestinal (GI) tract. Classically, there is an abrupt increase in pH on exit from the stomach, followed later by a sharp fall in pH, attributed to passage through the ileocecal region. However, the precise location of this latter pH change has never been conclusively substantiated. We aimed to determine the site of fall in pH using a dual-scintigraphic technique. On day 1, 13 healthy subjects underwent nasal intubation with a 3-m-long catheter, which was allowed to progress to the distal ileum. On day 2, subjects ingested a pH-sensitive wireless motility capsule labeled with 4 MBq [sup.51]Chromium [EDTA]. The course of this, as it travelled through the GI tract, was assessed with a single-headed [gamma]-camera using static and dynamic scans. Capsule progression was plotted relative to a background of 4 MBq [sup.111]Indium [diethylenetriamine penta-acetic acid] administered through the catheter. Intraluminal pH, as recorded by the capsule, was monitored continuously, and position of the capsule relative to pH was established. A sharp fall in pH was recorded in all subjects; position of the capsule relative to this was accurately determined anatomically in 9/13 subjects. In these nine subjects, a pH drop of 1.5 [+ or -] 0.2 U, from 7.6 [+ or -] 0.05 to 6.1 [+ or -] 0.1 occurred a median of 7.5 min (1-16) after passage through the ileocecal valve; location was either in the cecum (n = 5), ascending colon (n = 2), or coincident with a move from the cecum to ascending colon (n = 2). This study provides conclusive evidence that the fall in pH seen within the ileocolonic region actually occurs in the proximal colon. This phenomenon can be used as a biomarker of transition between the small and large bowel and validates assessment of regional GI motility using capsule technology that incorporates pH measurement. pH profile; wireless (telemetric) capsule doi: 10.1152/ajpgi.00127.2010.

We used radiotelemetry to investigate the spatial behavior of wintering Bicknell's Thrushes (Catharus bicknelli) at a mid-elevation rainforest site and a high-elevation cloud-forest site in the Dominican Republic. We also analyzed blood stable carbon isotopes and fecal samples to compare thrush diets at these two floristically and climatically distinct sites. Birds consumed a primarily fruit-based diet at the mid-elevation site and a primarily arthropod-based diet at the high-elevation site. Despite these dietary differences, individuals at both sites defended and maintained exclusive, minimally overlapping core use areas and home ranges. The mean size of both core use areas and home ranges was similar between males and females and between adults and first-winter birds. Presence of nonterritorial or 'floater' individuals was low at both sites (2.7% and 5.6%). Birds at the arthropod-dominated site were observed significantly more often on or within i m of the ground than birds at the fruit-heavy site, which were more often observed in the mid-canopy structure above 2 m. Birds at both sites displayed agonistic behaviors toward conspecifics and toward playback of conspecific vocalizations. Exclusive territoriality was the predominant winter social system, and we suggest that both arthropods and fruit are defensible resources for wintering Bicknell's Thrushes. Received 31 August 2009, accepted 13 January 2010. Key words: Bicknell's Thrush, Catharus bicknelli, Nearctic--Neotropical migrant, nonbreeding diet, radiotelemetry, winter social system. Utilizamos radiotelemetria para investigar el comportamiento espacial de individuos invernantes de la especie Catharus bicknelli en un bosque humedo ubicado a elevaciones medias y en un bosque nublado de alta elevacion en la Republica Dominicana. Tambien analizamos isotopos estables de carbono en la sangre y muestras fecales para comparar la dieta de las aves entre estos dos sitios, que son florisitica y climaticamente distintos. Las aves consumieron una dieta principalmente basada en frutos en el sitio de elevaciones medias y una principalmente basada en artropodos en el de elevaciones altas. A pesar de esas diferencias dietarias, los individuos de ambos sitios defendieron y mantuvieron areas nucleares de uso y ambitos hogarefios exclusivos, con minima superposicion. El tamano medio de tanto las areas nucleares de uso como de los ambitos hogarenos fue similiar entre machos y hembras, y entre adultos y aves en su primer invierno. La presencia de individuos no territoriales o 'flotantes' fue baja en ambos sitios (2.7% y 5.6%). Las aves del sitio dominado por artropodos se observaron con una frecuencia significativamente mayor en el suelo o a 1 m de este que las aves del sitio dominado por frutas, las cuales se observaron con mayor frecuencia en la estructura del dosel medio por encima de 2 m. Las aves de ambos sitios exhibieron comportamientos agresivos ante individuos coespecificos y ante la reproduccion de vocalizaciones coespecificas grabadas previamente. La territorialidad exclusiva fue el sistema social predominante del invierno y sugerimos que tanto los artropodos como las frutas son recursos defendibles por parte de los individuos invernantes de C. bicknelli. DOI: 10.1525/auk.2010.09160

We used radiotelemetry to evaluate at-sea habitat use by Cassin's Auklets (Ptychoramphus aleuticus) that bred at Prince Island, off southern California, from 1999 through 2001. We used logistic regression to compare paired radiotelemetry (presence) with random (pseudo-absence) location-associated habitat variables derived from (1) satellite remote-sensing of sea surface temperature and chlorophyll-a concentration and (2) bathymetry. Compared with random locations within their foraging area and after controlling for distance to colony, odds ratios indicated that Cassin's Auklets with dependent young occurred in relatively shallower, warmer, and chlorophyll-rich water associated with chlorophyll fronts near the insular shelf break. These oceanographic features characterize habitats that support key euphausiid prey (e.g., Thysanoessa spinifera) and also other krill predators. Radiotelemetry combined with satellite remote-sensing of the ocean provides an alternative to vessel-based surveys for evaluating seabird foraging habitats. In the absence of information on the actual distribution, abundance, and, hence, availability of zooplankton prey for seabirds, environmental factors can serve as proxies to help elucidate distributional patterns of seabirds at sea. Received 10 September 2008, accepted 27 December 2009. Key words: California Bight, California Current, Cassin's Auklet, logistic regression, Ptychorarnphus aleuticus, radiotelemetry, southern seabird foraging habitat. Utilizamos radiotelemetria para evaluar el uso de habitat marino de individuos de Ptychoramphus aleuticus que anidan en la isla Prince, en el sur de California entre los anos 1999 y 2001. Usamos regresion logistica para comparar las localizaciones de habitat de forrajeo obtenidas con telemetria (presencias) con puntos escogidos al azar (pseudo-ausencias) asociadas a tres variables medioambientales obtenidas a partir de imagenes satelitales, concentracion de clorofila-a y temperatura de superficie, y de datos de batimetria. Despues de controlar por el efecto de la distancia a la colonia, el analisis revelo que los individuos de P. aleuticus con crias ocupaban las aguas menos profundas, mas calientes y con concentraciones de cloronla mas altas. Estas caracteristicas, que identifican las zonas de frentes oceanograficos al borde de la plataforma peri-insular, tembien definen los habitats de los eufausidos que son presas clave (e.g., Thysanoessa spinifera) y de otros depredadores de krill. En comparacion con los metodos de muestreo que utilizan embarcaciones, el uso conjunto de radiotelemetria con datos obtenidos de imagenes satelitales proporciono una forma alternativa para el estudio los habitats de forrajeo de las aves marinas. Este metodo es especialmente util en situaciones donde la falta de informacion sobre la distribucion y abundancia del zooplancton imposibilita la evaluacion de la disponibilidad de recursos para las aves marinas. En estos casos, el uso de variables medioambientales obtenidas indirectamente a traves de imagenes satelitales puede facilitar el estudio de la distribucion de las aves en el mar. DOI: 10.1525/auk.2010.09273

Ascorbic acid (AA), one of the principal micronutrients in horticultural crops, plays a key role in the human metabolism, and its determination in food products has a great significance. Citrus fruits are rich in AA, but its content is highly susceptible to change during postharvest processing and storage. We present a new ultralow-cost system, constituted of an amperometric microsensor composed of three rod carbon electrodes connected to a telemetric device, for online detection of AA in orange juice, as an alternative to conventional analytical methods. The in vitro calibration, ranged from 0 to 5 mM, and AA juice content was calculated by adding low volumes of sample into an acetate buffer solution at a constant potential of +120 mV vs carbon pseudoreference. This new approach, which is simple, expandable, and inexpensive, seems appropriate for large scale commercial use. 10.1021/ac100303p

Recent studies have applied state space models to satellite telemetry data in order to remove noise from raw location estimates and infer the true tracks of animals. However, while the resulting tracks may appear plausible, it is difficult to determine the accuracy of the estimated positions, especially for position estimates interpolated to times between satellite locations. In this study, we use data from two gray seals (Halichoerus grypus) carrying tags that transmitted Fastloc GPS positions via Argos satellites. This combination of Service Argos data and highly accurate GPS data allowed examination of the accuracy of state--space position estimates and their uncertainty derived from satellite telemetry data. After applying a speed filter to remove aberrant satellite telemetry locations, we fit a continuous-time Kalman filter to estimate the parameters of a random walk, used Kalman smoothing to infer positions at the times of the GPS measurements, and then compared the filtered telemetry estimates with the actual GPS measurements. We investigated the effect of varying maximum speed thresholds in the speed-filtering algorithm on the root mean-square error (RMSE) estimates and used minimum RMSE as a criterion to guide the final choice of speed threshold. The optimal speed thresholds differed between the two animals (1.1 m/s and 2.5 m/s) and retained 50% and 65% of the data for each seal. However, using a speed filter of 1.1 m/s resulted in very similar RMSE for both animals. For the two seals, the RMSE of the Kalman-filtered estimates of location were 5.9 and 12.76 kin, respectively, and 75% of the modeled positions had errors less than 6.25 km and 11.7 km for each seal. Confidence interval coverage was close to correct at typical levels (80-95%), although it tended to be overly generous at smaller sizes. The reliability of uncertainty estimates was also affected by the chosen speed threshold. The combination of speed and Kalman filtering allows for effective calculation of location and also indicates the limits of accuracy when correcting service Argos locations and linking satellite telemetry data to spatial covariate and habitat data. Key words: Argos error; Fastloc GPS; gray seal; Halichoerus grypus; Kalman filter; marine mammals; state--space model.

A multipath propagation model for aeronautical telemetry over water at 8.0 GHz is presented. Data recorded during channel sounding experiments, conducted over the Pacific Ocean near Point Mugu, CA was used to model the multipath propagation. The modeling results show that a three-ray model consisting of line-of-sight propagation and two reflected propagation paths is a good fit for the measured channel frequency responses. One of the reflected propagation paths is a strong specular reflection determined by the geometry defined by the airborne transmitter, the ground-based receiver, and the sea surface. For the flight profiles used, the delay of this path is between 10 and 50 ns. The other propagation path is a more diffuse, random reflection whose amplitude is significantly smaller than the amplitude of the specular reflection and whose mean excess delay is 57 ns with an rms delay spread of 25 ns.

The arterial baroreflex is a fundamental reflex that buffers rapid changes in arterial blood pressure (BP) via regulation of the heart rate and sympathetic nerve activity to the vasculature. In adults a sigmoidal relationship between BP and both heart rate and sympathetic nerve activity is well documented. Its role in blood pressure control before birth is unclear. Preterm babies have a high incidence of low BP, especially in the first few days of life, which could be related, in part, to immaturity of the baroreflex. In the present study, we investigated the baroreflex control of fetal heart rate and renal sympathetic nerve activity (RSNA) in preterm fetal sheep in utero (102 [+ or -] 1 days of gestation; term 140 days). Phenylephrine was associated with a significant increase in BP from 38 [+ or -] 2 to 58 [+ or -] 3 mmHg and a decrease in heart rate (HR) from 177 [+ or -] 4 to 116 [+ or -] 8 beats per minute (bpm). Sodium nitroprusside was associated with a significant fall in BP from 38 [+ or -] 2 to 26 [+ or -] 1 mmHg and an increase in HR from 182 [+ or -] 4 to 274 [+ or -] 8 bpm. However, the time between the 50% changes in BP and HR was significantly greater after hypotension than hypertension (31 [+ or -] 8 s vs. 14 [+ or -] 5 s, P < 0.05). No significant changes in RSNA occurred with either stimulus. This suggests that there are different maturational tempos for the components of the central autonomic response to altered blood pressure. telemetry; renal sympathetic nerve

The db/db mouse is a genetic model of type 2 diabetes that exhibits progressive renal disease. Obesity, hyperglycemia, and albuminuria (822 [+ or -] 365 vs. 28 [+ or -] 8 [micro]g/day) are evident in 18-wk-old db/db compared with db/m (lean littermate control) mice. Our goal was to determine the blood pressure (BP) phenotype of the db/db mouse. Mean arterial BP measured in conscious mice by radiotelemetry was not different between db/db (n = 9) and db/m (n = 12) mice, averaging 113 [+ or -] 3 and 112 [+ or -] 2 mmHg, respectively. The circadian BP profile of db/db mice was shifted to the left and exhibited a significant reduction in amplitude compared with db/m mice. Heart rate (487 [+ or -] 9 vs. 542 [+ or -] 7 beats/min; P < 0.05) and locomotor activity were significantly reduced in db/db compared with db/m mice. We tested the hypothesis that intact afferent arteriole (AA) responsiveness to increases in renal artery pressure (RAP) and angiotensin (ANG) II sensitivity contributes to normal BP in this diabetic model. AA diameters of in vitro blood-perfused juxtamedullary nephrons of db/db mice (15.7 [+ or -] 0.5 [micro]m; n = 38) were significantly larger than those of db/m mice (12.5 [+ or -] 0.4 [micro]m; n = 37). AA responses to increases in RAP and ANG II were not different between kidneys of db/db and db/m mice. Significant AA vasoconstriction to 1 nM ANG II was observed in kidneys of db/db mice (-11 [+ or -] 4%), while 10 nM ANG II decreased AA diameter in both groups [db/db, -20 [+ or -] 4%, (n = 12); db/m, -26 [+ or -] 4% (n = 12)]. In summary, AA responses to increases in renal perfusion pressure and ANG II remain intact in db/db mice. Diabetic renal disease occurs in db/db mice independently of elevated BP. radiotelemetry; juxtamedullary nephron; angiotensin II; hyperglycemia

The present study was designed to take advantage of telemetry data acquisition and develop an easy and reliable system to servocontrol renal perfusion pressure (RPP). Digitized pressure signals from lower abdominal aorta in rats, reflecting RPP, was obtained by a telemetry device and dynamically exported into an Excel worksheet. A computer program (LabVIEW) compared the RPP data with a preselected pressure range and drove a bidirectional syringe pump to control the inflation of a vascular occluder around the aorta above renal arteries. When RPP was higher than the preselected range, the syringe pump inflated the occluder and decreased RPP, and vice versa. If RPP was within range, there was no action. In this way, RPP was servocontrolled within the desired range. In experiments with norepinephrine- or ANG II-induced acute increases in systemic arterial pressure (120-145 mmHg), the system controlled RPP at a constant range of 100-105 mmHg within 30-50 s and differentiated the pressure-dependent and -independent effects on renal functions. In Dahl S rats with high-salt-induced hypertension, this system maintained RPP at 100-120 mmHg over 10 days, while systemic arterial pressures were 150 [+ or -] 5.9 mmHg in uncontrolled animals. This system also has the ability of simultaneity and multiplexing to control multiple animals. Our results suggest that this is an effective and reliable system to servocontrol RPP, which can be easily established with general computer knowledge. This system provides a powerful tool and may greatly facilitate the studies in pressure-dependent/-independent effects of a variety of cardiovascular factors. LabVIEW; pressure dependent; urinary sodium excretion; renal blood flow

The use of analog circuits to reduce the size and power consumption of channel decoders such as Viterbi decoders has been an active area of research over the recent years. However, the need for digital memory to store the history of the path elimination decisions in a Viterbi decoder, limits the potential advantages that could be offered by an all-analog convolutional decoder implementation. This is especially so in cases where the use of an older silicon process technology is dictated by the application; hence, the power-reduction benefits offered by deep sub-micrometer digital designs cannot be exploited. A novel alternative convolutional decoding method which allows for an entirely analog implementation is the modified feedback decoding algorithm (MFDA). This paper describes the first integrated realization of a convolutional decoder employing the MFDA. The rate-1/2, constraint-length-3 decoder, employs a current-mode analog signal processing core and was fabricated in a 0.6-[micro]m CMOS process technology, occupying an area of 0.5 [mm.sup.2]. Measured results show that decoding speeds in excess of 1-Mb/s are possible with virtually no loss in coding gain. Total power consumption is 2.45 mW from a single 3-V supply. Although a hard-decision decoder, conversion to soft-decision decoding requires only the inclusion of a simple analog delay line as shown in the paper. The decoder is dedicated to an implantable biotelemetry system, but it can also find use in other low-power applications. System-level coding simulations are also presented which are useful for the construction of larger decoders where the benefits of the MFDA approach would be more pronounced. Index Terms--Analog decoder, convolutional codes, current-mode circuits, implanted devices, modified feedback decoding algorithm (MFDA), telemetry, Viterbi decoder.

The fragmentation of forests by the expansion of agriculture is recognized as an important factor influencing worldwide declines of forest-dependent species. Species that are forest dependent may be especially vulnerable to fragmentation because they have specialized resource requirements and may exhibit lower mobility in an agricultural matrix. We investigated movement patterns and resource selection of forest-dependent northern long-eared myotis (Myotis septentrionalis) in a forest-agricultural landscape on Prince Edward Island, Canada. Radiotelemetry was used to locate day-roosts and to estimate locations of female bats during nightly foraging bouts. Day-roost locations and foraging areas were mapped using a geographic information system to generally characterize the forest cover of foraging and roosting areas. Vegetative structure and insect prey availability were measured in the field and compared between foraging and roosting areas to describe resource selection at these sites. Movements of female northern long-eared myotis were constrained to forest features and foraging areas were concentrated along forest-covered creeks with bats roosting predominantly in deciduous trees within the same forest fragment, although bats at 1 site seemed to exclusively use a barn during late pregnancy and lactation. Differences in prey availability did not explain the spatial segregation of roosting and foraging areas. Relative to roost areas foraging sites were more likely to be close to forested creeks and densely forested areas, whereas roost sites were characterized by the availability of potentially suitable roosts. This study demonstrates the importance of investigating movements and resource selection of individuals in fragmented landscapes because a specialization on forest resources can highly restrict the vagility of forest-dependent species to a local environment. Key words: Chiroptera, forest fragmentation, forest structure, Prince Edward Island, radiotelemetry, roost trees

This paper presents a production-oriented chip-set to be used as the circuitry needed to implement the necessary RF functionalities of a new generation of S-band satellite transponders for telemetry tacking and control (TT&C) applications. The RF hardware section integration is achieved by means of a customized chip-set of just four multi-chip multifunction MMIC (MCMM) modules. The functions contained in the monolithic microwave integrated circuits (MMICs) include the active circuits needed for the front-end low noise amplifier (LNA), the RF and IF converters, all the variable gain amplifiers (VGAs), the Voltage Controlled Oscillatar (VCO) for both transmit and receive sections, the frequency prescaler and multiplier needed to synthesize the frequency plan as well as the Local Oscillatar (LO) amplifiers. The selected technology is GaAs, mainly due to its radiation hardness, essential for aerospace applications, and good reliability. Issues such as suitable circuit topology, efficient dc biasing, circuit area minimization, cost-oriented system design and advanced packaging techniques have been addressed during the design. Measurements and yield results from the manufactured circuits will be presented showing that these components, even though especially designed in the frame of the GALILEO TT&C transponder predevelopment, are suitable for a variety of missions, from Deep space to near Earth, including spread-spectrum transponders with precision ranging function.

Wireless microwave telemetry addresses the difficult issue of obtaining transducer outputs from reciprocating and rotating components through the use of advanced electronic components. This eliminates the requirements of a direct link between the transducer and the acquisition system. Accuracy of the transducer signal is maintained through the use of a double frequency modulation technique which provides temperature stability and a 20 point calibration of the complete system. Multiple transmitters can be used for larger applications and multiple antennas can be used to improve the signal strength and reduce the possibility of dropouts. Examples of automotive torque converter and piston temperature measurements are provided, showing the effectiveness of the wireless measuring technique. [DOI: 10.1115/1.2771562] Keywords: telemetry, torque converter, piston temperature, data acquisition

This paper describes a preliminary experimental investigation to convey acceleration measurements, made on-board an electromagnetic (EM) launched projectile, using microwave telemetry techniques. The focus of the investigation is to extend the Hardened Subminiature Telemetry and Sensor Systems (HSTSS) technology for use in EM launch environments. Many aspects of the HSTSS technology have already been successfully demonstrated in high-G, high-pressure launch environments in conventional gun systems. In addition, microwave transmission in stationary experiments, where the telemetry package was exposed to relatively high magnetic fields and EM transients in a railgun launcher, has been demonstrated. However, microwave telemetry during an EM launch has not been demonstrated until now. In this work, setback acceleration measurements obtained with an on-board accelerometer were processed by HSTSS electronics and transmitted simultaneously during launch via an antenna located in front of the EM launch package. While only the test conducted at 9-kG peak acceleration provided the most useful data, detailed analyses suggest that mechanical problems--rather than the microwave telemetry process itself--were probably responsible for difficulties experienced at higher accelerations. This paper reviews the experimental methodology and discusses the results of the investigation. Index Terms--Accelerometer, FM, hardened, RF, S-band.

Issues relating to the use of radiotelemetry when studying animal behaviour patterns are discussed. A former study looked at the use of capture patches for lynx. The effects of the capture event on subsequent movement patterns are studied.

Researchers examined the effects of two different methods of attaching radio transmitters to mallards, as some experts have expressed concern that the use of abdominal implants affects wildfowl behaviour and survival. The researchers compared the use of transmitters attached to the backs of birds against abdominally implanted transmitters. The results indicated that the back-anchored packages may have had a negative impact on reproduction and, at one of the five sites, the females with backpacks had a significantly higher mortality rate than those with abdominal implants.

I studied survival of 100 radio-tagged gray partridge (Perdix perdix) in North Dakota from winter to the beginning of nesting during 1985-87. Radio transmitters appeared to cause significant mortality among captured partridge (34%) during the first week postrelease, after accounting for mortality expected from other sources. Survival of partridge living >7 days posttrapping (n = 55) from early January to 1 May was 38%. The major source of mortality after the first week was raptor predation. A Cox's proportional hazards analysis revealed that body mass (P = 0.003) and sex (P = 0.04) were significantly related to probability of survival. Partridge weighing [is greater than or equal to]400 g had higher survival (50%) than those weighing

Sixty-nine radio-telemetry papers published from 1986-92 were reviewed to determine the extent to which authors employed and reported error measures for radio telemetry data. Results showed that there is inadequate use and reportiing of error measures, which could lead to misinterpretation of data. The importance of estimating and reporting the precision of radio tracking data is reiterated.

We assessed 3 methods of estimating daily activity patterns in the Egyptian mongoose (Herpestes ichneumon): net activity time (M1), percentage of localizations with activity (M2), and distance traveled (M3). The 3 methods gave similar results ([r.sub.s] > 0.89, P < 0.0001). With M1 and M2 7 days of tracking were necessary for obtaining a consistent activity pattern ([r.sub.s] = 0.91), whereas 15 days were required for M3 ([r.sub.s] = 0.80).